Between one-third and one-half of individuals with autism display repetitive, self-injurious behavior, ranging from head banging to self-directed biting and punching. In cases of treatment-resistant self-injurious behavior, electroconvulsive therapy (ECT) can produce life-changing results, with more than 90 percent suppression of self-injurious behavior.
However, individuals with autism may require treatments as frequently as once every five days to sustain improvements obtained during the initial ECT course. ECT is associated with cognitive side effects, and the long-term consequences of frequent ECT over many years, sometimes starting in childhood, are unknown.
Irving Reti, director of the Brain Stimulation Program at Johns Hopkins Hospital in Baltimore, has treated a number of patients with autism who have severe self-injurious behavior using ECT. These patients have typically progressed to a frequent maintenance ECT regimen. One alternative he has considered for suppressing self-injurious behavior without the need for ECT is deep brain stimulation (DBS), which delivers electrical stimulation to a specific region of the brain via an implanted device without triggering a seizure.
To test the potential of DBS for self-injurious behavior in people with autism, the researchers plan to use mice with a genetic abnormality implicated in autism that also exhibit excessive self-grooming that causes injury. They have targeted a brain region in these mice that is used in DBS patients with treatment-resistant obsessive compulsive disorder. When the researchers administer either ECT or DBS to these mice, they exhibit a marked reduction in excessive self-grooming.
Ongoing studies aim to determine whether DBS suppresses excessive self-grooming when different brain regions are targeted. Because multiple genetic abnormalities contribute to autism, Reti also plans to assess DBS in a second mouse model of autism-related self-injurious behavior. Stimulation sites that work in both mouse models will be the strongest candidates for DBS in people with autism. Reti also hopes to determine the minimum stimulation time needed for DBS to be effective in order to minimize side effects, and to learn whether DBS maintains its effectiveness with repeated use.
